Means adjusting cylinder in printing press



Marchzl, 1961 J. G. GHORMLEY, JR, ET AL 2,975,708

MEANS ADJUSTING CYLINDER IN PRINTING PRESS Filed Jan. 11, 1960 JAMES 6. GHORMLE Y, JR. CLYDE 7. KITCHENS INVENTORS A 7'TOR/VE Y MEANS ADJUSTING CYLINDER IN PRINTING PRESS James G. Ghormley, Jr,, and Clyde T. Kitchens, Fort Worth, Tex., assignors to Ghormley Engineering and Manufacturing Company, Fort Worth, Tex, a corporation of Texas Filed Jan. 11, 1960, Ser. No. 1,736

5 Claims. (Cl. 101-248) This invention relates to printing presses and has reference to an improved register correcting mechanism for a chain driven press.

The equality of printing done on a high speed press is 'often dependent upon the accuracy with which successive superimposed impressions may be kept in register with one another. A mechanism which permits printing register to be adjusted during operation of a high speed press promotes the ultimate utility of high speed printing processes because it facilitates maintenance of quality standards without costly work stoppage. In my copending application No. 802,711, filed March 30, 1959, now US. Patent No. 2,949,851, a register correcting mechanism comprising an adjustably and pivotally mounted bell crank carrying two rotatably mounted sprockets is disclosed for operation with a chain driven press. The present invention is directed to a construction for a register correcting mechanism wherein a single lever mounted sprocket is used in conjunction with a slack compensating device to effect the same general result. Since the inclusion of a slack compensating device in a chain driven press has been found advantageous for purposes other than register correction, its exploitation as part of a correcting mechanism results in simplified construction of the present invention.

Accordingly, an object of the present invention is to provide improved and simplified means for adjusting a printing cylinder relative to an impression roller in a printing press.

Another object of the invention is to provide a single sprocket adjustment in a chain driven printing press to effect angular displacement ofone rotating part relative to another.

A further object of the invention is to provide a chain driven printing press wherein in adjustment mechanism of economical construction may be used to alter the register of printed images on opposite sides of printing stock.

Another object of the present invention is to provide a register adjustment mechanism for a printing press and wherein such mechanism may be accessible for removal or repair without disassembly of major components of the press.

, Still another object of the invention is to provide a mechanism whereby printing register may be adjusted during operation of a printing press.

These and other objects will become apparent from the following description and the accompanying drawing, wherein:

The figure is an elevational side view of a' printing press with a portion of its outer wall removed to show internal features of its construction and operation.

In the drawing, a box-like housing, generally indicated by the numeral 10, is shown with its upper forward corner 11 truncated. Within the housing an upper impres- United States Patent sion roller 12 comprising a horizontally disposed metal 7 cylinder carrying an integrally formed mat of resilient material, such as India rubber upon and coextensive with v ce its peripheral surface, is coaxially secured to a rotatably mounted shaft 13 the outer end of which extends perpendicularly through and projects exteriorly of an outer vertical wall 14 of the box-like housing 10. A sprocket 15 is secured to the outer end of the shaft 13 of the upper impression roller 12 exteriorly of the housing 10. An upper plate cylinder 16 (indicated by dotted lines), identical in diameter the upper impression roller 12, is positioned within the housing 10 adjacently rearward of and above the upper impression roller 12 and is coaxially secured to a rotatably mounted shaft 17 disposed parallel to the shaft 13 of the upper impression cylinder. The upper plate cylinder 16 is adapted to carry a photolithographic plate on its peripheral surface so that such plate will bear in running contact against the resilient surface of the'upper impression roller 12. Means for attaching and securing photolithographic plates to cylindrical members are well known in the art and any suitable method of attachment may be used with the present invention. A sprocket 18, identical in effective diameter to the sprocket 15 of the upper impression roller 12, is attached to the shaft 17 of the upper plate cylinder 16 exteriorly of the housing 10 and in the plane of the sprocket of the upper impression roller.

A lower impression roller 19 identical in size and construction with the upper impression roller 12 is positioned within the housing 10 immediately beneath the upper impression roller and is coaxially secured to a rotatably mounted shaft 20 parallel with the shaft 13 of the upper impression roller. A sprocket 21, identical in effective diameter to the previously described sprockets 15 and 18, is secured to the shaft 20 of the lower impression roller 19 exteriorly of the housing 10 and is positioned in the plane of the sprocket 15 of the upper impression roller 12. A lower plate cylinder 22 (indicated by dotted lines) is positioned adjacently beneath and rearwardly of the lower impression roller 19 within the housing 10 and is there coaxially secured to a shaft 23 parallel with the shaft 21 of the lower impression roller. The lower plate cylinder 22 is identical in size and construction to the upper plate cylinder 16. A sprocket 24, corresponding in effective diameter to the sprocket 21 of the lower impression roller 19, is mounted on the shaft 23 of the lower plate cylinder 22 exteriorly of the housing 10 and is likewise positioned in the plane of the sprockets 15, 18 and 21 described above.

A U-shaped mounting bracket 25 is attached to the outer vertical wall 14 at the truncated corner 11 of the housing 10 and projects outwardly thereof through the common plane of rotation of the above described sprockets. The mounting bracket 25 has a flat upper surface disposed at an angle of approximately 45 to ground level in alignment with the surface of the truncated portion 11 of the housing 10. A shank 26 is positioned with one of its ends adjacent the upper surface of the mounting bracket 15 and projects perpendicularly and forwardly therefrom. A flange 27 is integrally and coaxially formed with the lower end of the shank 26 so that the lower surface of the flange is flush with the upper surface of the mounting bracket. The principal axis of the shank 26 lies between the plane of sprockets 15, 18, 21 and 24 and the plane of the outer wall 14 of the housing 10. A bearing bracket 28 is positioned adjacently above the mounting bracket 25 and is provided with a recess in its lower surface to receive the flanged portion 27 of the shank 26 and is also provided with an opening above the recess through which the shank 26 projects. Bolts 29 pass through the hearing bracket 28 and threadedly engage the mounting bracket 25. A handle 30 is coaxially secured to the upper end of the shank 26 by a screw 31.

A bell crank 32 is located exteriorly of the housing at a position above the sprocket of the upper impression roller 12 and is pivotally connected intermediately of its ends to a stub shaft 33 projecting outwardly of'the outer wall 14 of the housing 10. A .pivot pin 34 is attached to one end of the bell crank 32 and projects outwardly thereof in a position parallel to the shafts 13, '7, 26 and 23 of the upper and lower impression rollers and plate cylinders. A sprocket 35 is rotatably mounted to the pivot pin 34 in the plane of rotation of the sprockets 15 and 18 of the upper and lower impression rollers 12 and 19. A yoke 36 provided with transversely aligned openings in its opposite ends is pivotally connected to a pin 37 passing through the other end of the bell crank 32. A threaded rod 38 extends from the closed portion of the yoke 36 through an opening in the base of the mounting bracket 25 to threaded engagement with an axial opening in the shank 26.

A drive sprocket 39" positioned at the lower forward corner of the housing 19 is secured to the end of a drive shaft 4%"; exteriorly of the housing. The drive shaft 40 is suitably coupled to an appropriate power source which may in turn be synchronously coupled to a number of printing presses as defined herein. A reduction idler 41 comprising two integrally and coaxially constructed sprockets of different diameters (the smaller being indicated by dotted lines) is rotatably mounted to an idler shaft 42 at the lower rear corner of the outer wall 14 of the housing 10. A plurality of driven sprockets 43, performing functions not a part of this invention, are rotatably mounted exteriorly of the housing 10 in the plane or rotation of the upper impression roller sprocket 15. These sprockets may be attached to selected members of trains of rollers (not shown) transporting ink and hydrophylic fluids to the plate cylinders 16 and 22.

A sprocket chain 44 extends from the lower periphery of the drive sprocket it to the lower periphery of the reduction idler 41 and then to successive engagements with some of the sprockets 43 and to engagement with the upper peripheral surface of the upper plate cylinder sprocket 18. The chain then runs to engagement with the lower surface of the sprocket 15 of the upper impression roller 12 and to subsequent engagement with the upper teeth of the bell crank sprocket 35, then to the lower teeth on the lower impression roller sprocket 21 and then to upper teeth on the sprocket 24 of the lower plate cylinder 22. The chain 44 then continues to the lower teeth of the drive sprocket 39 after engagement with the remaining driven sprockets 43.

Between the drive sprocket 33 and the reduction idler 4-1 a tension bar 45 is pivotally mounted to the forward wall 14 of the housing 10 in a vertical plane of motion by a pivot 46. A helical spring 47 is extended between one end of the tension bar and an opening 48 therebeneath in the forward wall 14 of the housing 10. A shaft 49 projects forwardly of the other end of the tension bar 45 and a tension sprocket 50 is rotatably mounted on the forward .end of the shaft in the plane of rotation of the drive sprocket 39. The chain 44 is engaged by upper teeth of the tension sprocket St) at a position between the drive sprocket 39 and the reduction idler 41.

Paper stock 51 is introduced into the housing 1!) through an opening (not shown) in the rear wall thereof and passes adjaccntly between the upper and lower impression rollers '12 and 19 leaving the press through another opening (not shown) in the forward wall of the rousing.

A reduction drive system sprocket 52 is rotatably mounted on a horizontal pin 53 in the lower part of the forward wall 14 of the housing It} above the tension bar 45. A reduction system chain 54 engages the reduction system sprocket 52 and also engages the smaller sprocket of the reduction idler -41. An inking oscillator (not shown) or other dependent mechanism of the press will contact on succeeding revolutions. the lower impression roller 19 and the lower plate cylinder may be driven by the reduction system sprocket 52. The illustrated construction and arrangement of reduction system components are here shown as one means of deriving supplemental motive force from a drive chain 44 which also coacts as part of a register correcting device.

In operation, the drive sprocket 39 is set in rotary motion by the power source and the chain 44 is accordingly set upon its course in engagement with the other sprockets. With reference to the drawing, counterclockwise rotation is imparted to the upper plate cylinder 16 and its sprocket 18, whereas the upper impression roller 12 and its sprocket 15 are carried in clockwise rotation. As the upper plate cylinder 16 rotates, the photolithographic plate carried at its peripheral surface is brought into contact with moisture and ink rollers (not shown) whereby it is inked on selected portions which are then brought into contact with the impression roller 15 which receives an inked impression in the image of the inked portion of the photolithographic plate. Since the upper plate cylinder sprocket 18 and the upper impression roller sprocket 15 are identical in diameter, their angular velocities are identical. Identical diameters of the upper plate cylinder 16 and the upper impression roller 12 assure that contacting points on one revolution In like manner,

22 are put in opposite directions of rotation with equal angular velocities so that any given point on the photolithographic plate carried by one will successively contact one point on the other. The rotations of the upper and lower impression rollers 12 and 19 are opposite to one another and are also equal in peripheral velocities so that images respectively transferred to the upper and lower surfaces of paper stock 51 passing therebetween remain in register with respect to one another. Between engagements with the upper and lower impression roller sprockets the chain 44 is conducted over the bell crank sprocket 35. Considering the drive sprocket 39 at rest, upon rotation of the knob 30 the threaded rod 38 within the shank 26 is either retracted or extended and the position of the yoke 36 is altered. The pivotal attachment of the bell crank 32 to the outer wall 14 of the housing 10 results in an angular displacement thereof as indicated by dotted lines, and the distance between the bell crank sprocket 35 and the upper impression roller sprocket 15 is increased. By this increase in distance, the chain 44 is extended and the upper impression roller 12 is rotated relative to the lower impression roller 19. When the press is in operation, the described adjustment accomplishes the same rotation of the upper impression roller 12 relative to the lower impression roller 19 by temporary alteration of their relative angular velocities. In .both instances, compensation for an increased effective length of the chain 44 is effected by displacement of the tension sprocket 50 urged against the chain by the spring 47.

The invention is not limited to the exemplary construction herein shown and described, but may be made in various ways within the scope of the appended claims.

What is claimed is:

1. In a printing press having an axially mounted plate cylinder and having an axially mounted impression roller: a sprocket coaxially secured to said plate cylinder, a sprocket coaxially secured to said impression roller, a bell crank pivotally mounted on said press in a plane of rotation parallel to the plane of rotation of said sprocket coaxially secured to said impression cylinder, a single sprocket rotatably secured to a projecting end of said bell crank in the plane of rotation of said sprocket coaxially secured to said impression roller, a shank rotatably attached to said press and having a threaded axial opening, a threaded rod engaging said threaded axial opening of said shank and extending to pivotal attachment to said bell crank, a sprocket chain engaging each of said tended in tension between the other end of said tension bar and said press, means driving said sprocket chain, and means carrying paper stock through said press and in contact with said impression roller.

2. In a chain driven printing press including an axially mounted plate cylinder and an axially mounted impression cylinder and having sprockets respectively mounted thereto in coplanar relationship to one another, a register correcting mechanism comprising: a bell crank pivotally mounted'to said press in a plane of angular displacement parallel to the plane of said sprockets, a single sprocket rotatably mounted on said bell crank in said plane of rotation of said sprockets, a tension bar pivotally mounted on said press, a sprocket rotatably mounted on one end of said tension bar in the plane of rotation of the aforesaid sprockets, a spring attached to and extended in tension between the other end of said tension bar and said press, a continuous chain engaging said sprockets in its course and engaging said sprocket of said impression cylinder intermediately of its respective engagements with said sprocket of said bell crank and said sprocket of said tension bar, means carrying paper Stock through said press and in contact with said impression roller, and means adjusting the position of said bell crank on its pivoted mounting.

3. A printing press comprising: a mounting frame, a first plate cylinder adapted to receive a photolithographic plate and axially mounted to said frame, a sprocket coaxially mounted to said first plate cylinder, a first impression roller having a resilient peripheral surface adapted for running engagement with said photolithographic plate on said first plate cylinder, a sprocket coaxially mounted to said first impression roller in the plane of said sprocket of said first plate cylinder, a second plate cylinder spaced from said first plate cylinder and axially mounted to said frame in a position parallel to said first plate cylinder, at sprocket coaxially secured to said second plate cylinder and positioned in said plane of rotation of the aforesaid sprockets, a second impression cylinder having a resilient peripheral surface adapted for running engagement with said second plate cylinder and positioned adjacent said first impression cylinder, a sprocket coaxially secured to said second impression cylinder, a bell crank pivotally mounted to said frame in a plane of pivotal adjustment parallel to said plane of rotation of the said sprockets, a sprocket rotatably mounted to said bell crank in said plane of rotation of said sprockets, means adjusting the angular position of said bell crank on its pivotal mounting, a tension bar pivotally mounted on said frame, a sprocket rotatably mounted on one end of said tension bar in said plane of rotation of said sprockets, a spring extended between the other end of said tension bar and said mounting frame, a continuous chain engaging said sprockets and engaging said sprocket rotatably mounted to said bell crank intermediately of engagement with said sprockets engaging said first and second impression rollers.

4. In a chain driven printing press including an axially mounted plate cylinder and an axially mounted impression roller and having sprockets respectively mounted thereto in coplanar relationship to one another, a register correcting mechanism comprising: a bell crank pivotally mounted to said press in a plane of rotation parallel to the plane of said sprockets, a single sprocket rotatably mounted on said bell crank in said plane of rotation of said sprockets, a continuous chain engaging said sprockets engaging said sprocket on said bell crank intermediate said engagement with the other said sprockets, means adjusting the position of said bell crank on its pivoted mounting, slack compensating means engaging said chain, and means carrying paper stock through said press and in contact with said impression roller.

5. In a chain driven printing press including a pair of impression cylinders positioned for simultaneous contact with opposite sides of paper stock positioned therebetween, a sprocket coaxially mounted on one of said cylinders, a second sprocket coaxially mounted on the other of said cylinders and disposed in coplanar relationship with the first said sprocket, a bell crank pivotally mounted for angular displacement in a plane parallel to, the common plane of said sprockets, a third sprocket rotatably mounted on an end of said bell crank for rotation in the common plane of said first and second sprockets, a chain engaging the first said sprocket and thence running to and engaging said third sprocket and thence running to and engaging said second sprocket so that the course of said chain imparts opposite directions of rotation to said first and second sprockets, a fourth sprocket engaging said chain, tensioned means urging said fourth sprocket against said chain, and means adjusting the angular position of said bell crank.

References Cited in the file of this patent UNITED STATES PATENTS 

